摘要
本文研究了海水中氨基酸对金属离子M(Ⅱ)-δ-MnO_(2)离子交换的影响。实验结果表明,在pH=1—8.5时,较高浓度(20.00ppm)谷氨酸、甘氨酸和丙氨酸以及低浓度(0.20ppm)组氨酸对Cd(Ⅱ),Zn(Ⅱ)-δ-MnO_(2)离子交换没有影响,而较高浓度(20.00ppm)组氨酸则有较大影响,其影响程度是Cu(Ⅱ)>Cd(Ⅱ)>Zn(Ⅱ),该序列与胺抑制影响因子F(ψ)序列相同。这进一步证明氨基酸在δ-MnO_(2)表面脱羧成胺,然后胺通过与M(Ⅱ)络合和表面吸附来抑制M(Ⅱ)-δ-MnO_(2)离子交换。加入氨基酸时的M(Ⅱ)-δ-MnO_(2)离子交换等温线仍为L-F-3型,且可用表面分级离子交换理论之等温式描述。
This paper studies the effect of amino acids on Cd(II),Zn(II)-δ-MnMnO_(2)ion-exchange in seawater.The experimental results indicate that the alanine,glycine and glutamic acid influence not the Cd(II),Zn(II)-δ-MnMnO_(2)ion-exchange,and that the histidine of higher concentration displaces Cd(II)%,Zn(II)%-pH curve rightward,that is to say,inhibits Cd(II),Zn(II)-δ-MnMnO_(2)ion-exchange,which have not been reported in literature.The sequence-inhibiting of hislidinc on Cu(II),Zn(II)and Cd(II)-δ-MnMnO_(2)ion-exchange can be explained by effectinhibi-ting factor of organics Forg(φ),which was induced from chemical equilibrium principle.The mechanism that the amino acid inhibits M(II)-δ-MnMnO_(2)ion-exchange includes two steps.The amino acid first changes into amine on surface of 8-MnMnO_(2).The M(II)-amine complex in liquid,which competes with-MnMnO_(2)for M(II),then inhibits the M(II)-δ-MnMnO_(2)ion-exchange,thus decreasing the surface site-exchanging of 6-MnMnO_(2)due to absorption of amine on-MnMnO_(2)which also inhibits the M(II)-δ-MnMnO_(2)ion-exchange.The Cd(II)-δ-MnMnO_(2)ion-exchange isotherm in existence of amino acid is also classed by Gills-zhang Zhengbin classification.The ion-exchange isotherm in existence of glycine is the same as that without amino acid,while isotherm in existence of histidine of higher concentration displaces isotherm without the existence of amino acid downward,that is to say,the histidine inhibits Cd(II)-δ-MnMnO_(2)ion-exchange.The ion-exchange isotherm in existence of all amino acids can be estimated by theory of interfacial siepwise ion-exchange.The conclusions resulted from ion-exchange isotherm is consistent with M(II)%-pH curve,and the conclusion that the histidine influences greatly Cd(II),Zn(II)-δ-MnMnO_(2)ion-exchange is very important.
作者
张正斌
刘莲生
王修林
张文生
Zhang Zhengbin;Liu Liansheng;Wang Xiulin;Zhang Wensheng(Shandong Collcge of Oceanology,Qingdao)
出处
《海洋与湖沼》
1987年第5期450-458,共9页
Oceanologia Et Limnologia Sinica
基金
国家自然科学基金资助课题
